Study: Yogurt Makes Mice Slimmer, Sexier … What About Humans?

Eating yogurt has quite an effect on the sex appeal of
mice, and even makes them slimmer, according to new research out of the Massachusetts Institute of Technology. Now that we know Minnie Mouse's secret, what does this have to do with you?

“We started these studies to learn whether probiotic bacteria in yogurt may impact age-associated weight gain and affiliated diseases such as cancer,” Professor Susan Erdman, an immunobiologist, told HealthySELF of the research she’s doing with fellow MIT professor Eric Alm, an evolutionary geneticist.

For their study, which is ongoing, Alm and Erdman divided 40 male mice and 40 female mice into two groups, feeding one group a diet of “junk food” (high in fat, low in fiber), and the other group regular mouse meals. Then, they added vanilla-flavored yogurt to the diets of half of each group.

“The first thing we noticed was that yogurt-eating mice were very shiny,” says Erdman. “The other very noteworthy thing was that male mice had a sassy attitude. It’s similar to how men at the top of their game carry themselves differently. We see that sort of sexy swagger in the yogurt-eating male mice. In general, these were shiny, sexy mice.”

As it turns out, no matter which group (junk food or “regular mouse” food) the mice are in, if they eat yogurt, they not only have much shinier coats, but they’re also slimmer! Plus — the male yogurt-eating mice have bigger testicles than mice who don’t eat yogurt, which perhaps accounts for the sexy swagger.

Here’s where it gets even crazier: The females who eat yogurt are “better” mothers. Erdman explains that mother mice that eat probiotics — beneficial live bacteria used in making yogurt — have higher success rates in raising their babies to weaning age, with fewer events of maternal neglect. “We don’t know why this happens,” she says. “Perhaps it’s related to lower stress levels in yogurt-eating mice? We’re currently researching this further.”

So what’s the deal for humans? Can yogurt make us slimmer and sexier, too? “Well, there’s lots of potential for improving human health,” says Erdman, noting that a recent New England Journal of Medicine paper showed that humans are slimmer when regularly eating yogurt, and another study is investigating implications of probiotics and fertility in humans.

SELF contributing editors Stephanie Clarke and Willow Jarosh, registered dietitians and co-founders of C&J Nutrition, say it would be jumping the gun to draw any type of conclusion from this study alone. “Some things to consider are whether the yogurt is organic or not and exactly what the rest of the two diets consists of,” they point out.

However, they add, it is known that there are many reasons yogurt is good for you when incorporated into an overall healthful diet.

“Yogurt, especially Greek yogurt, is a good source of protein, which may help you feel more satiated at meals, helping to decrease overeating,” say Clarke and Jarosh. “In addition, yogurt is a good source of calcium and magnesium, both of which are important minerals for bone health.”

When it comes to probiotics specifically, Clarke and Jarosh say, “Over recent years, there has been continued research on the health benefits of probiotics. These live organisms, when consumed in appropriate amounts, have a beneficial effect on the host (you!).” These benefits, they say, “range from helping to decrease diarrhea after antibiotic use to improving Irritable Bowel Syndrome to reducing the risk of recurring bladder cancer to reducing the severity of colds.”